Poland's deputy prime minister, Andrzej Lepper, has been sacked after just four months as the country's right-wing government collapsed amid acrimony.

Mr Lepper, leader of the ultra-nationalist Self Defence Party, lost his job after an explosive row with the Prime Minister, Jaroslaw Kaczyinski. The premier's Law and Justice Party has given itself until Monday to try to put together a parliamentary majority and try to avoid fresh elections, which would probably be held on 26 November.

The political crisis is another example of instability in the former Communist states that joined the EU two years ago, amid the turmoil in Hungary where there are mass protests after the Prime Minister admitted he lied to win an election. Mr Kaczyinski said Mr Lepper had been given "a chance to participate in a good government", adding: "He failed to use this opportunity and after a short while he returned to his old practices, to troublemaking." Mr Lepper hit backon television, describing the behaviour of Mr Kaczynski, and his identical twin brother Lech, who is Poland's President, as "boorishness, boorishness and again boorishness".

He accused the Prime Minister of failing to consult, ignoring agreements and belittling him, and added that the Kaczynski brothers "are not made for constructing, but for destroying. They will agree only with people who are on their knees before them".

Mr Lepper, a former pig farmer, had clashed several times with the Prime Minister over public spending, calling for more aid for the countryside. He also complained that a decision to send a reinforcement of Polish soldiers to the Nato force in Afghanistan was taken without consultation.

Commentators said that the clash between the two was inevitable. Though Self Defence is a more extreme party than Law and Justice, both are nationalist in their outlook and compete for the same voters.

Mr Lepper, who has long-term ambitions to become president, has been taking an increasingly populist position, perhaps worried that Law and Justice is eating into his traditional base of support.Mr Kaczyinski now faces an uphill battle to try to assemble a majority in parliament.The Prime Minister could appeal to members of Mr Lepper's party to continue supporting the government without him. Alternatively he could seek to recruit another small party to eke out a majority.

Even if he is successful, the new government is likely to prove extremely fragile. This is the second crisis for the new government in recent months. The initial prime minister, Kazimierz Marcinkiewicz, was sacked by Lech Kaczyinski, who installed his twin brother despite an earlier pledge not to do so.

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